Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Stem Cells Transl Med ; 8(8): 822-832, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31037857

RESUMO

We previously demonstrated that intracardiac delivery of autologous peripheral blood-derived CD34+ stem cells (SCs), mobilized by granulocyte-colony stimulating factor (G-CSF) and collected by leukapheresis after myocardial infarction, structurally and functionally repaired the damaged myocardial area. When used for cardiac indication, CD34+ cells are now considered as Advanced Therapy Medicinal Products (ATMPs). We have industrialized their production by developing an automated device for ex vivo CD34+ -SC expansion, starting from a whole blood (WB) sample. Blood samples were collected from healthy donors after G-CSF mobilization. Manufacturing procedures included: (a) isolation of total nuclear cells, (b) CD34+ immunoselection, (c) expansion and cell culture recovery in the device, and (d) expanded CD34+ cell immunoselection and formulation. The assessment of CD34+ cell counts, viability, and immunophenotype and sterility tests were performed as quality tests. We established graft acceptance criteria and performed validation processes in three cell therapy centers. 59.4 × 106 ± 36.8 × 106 viable CD34+ cells were reproducibly generated as the final product from 220 ml WB containing 17.1 × 106 ± 8.1 × 106 viable CD34+ cells. CD34+ identity, genetic stability, and telomere length were consistent with those of basal CD34+ cells. Gram staining and mycoplasma and endotoxin analyses were negative in all cases. We confirmed the therapeutic efficacy of both CD34+ -cell categories in experimental acute myocardial infarct (AMI) in immunodeficient rats during preclinical studies. This reproducible, automated, and standardized expansion process produces high numbers of CD34+ cells corresponding to the approved ATMP and paves the way for a phase I/IIb study in AMI, which is currently recruiting patients. Stem Cells Translational Medicine 2019;8:822&832.


Assuntos
Antígenos CD34/genética , Automação Laboratorial/métodos , Citometria de Fluxo/métodos , Infarto do Miocárdio/terapia , Transplante de Células-Tronco de Sangue Periférico/métodos , Células-Tronco de Sangue Periférico/citologia , Adulto , Animais , Antígenos CD34/metabolismo , Células Cultivadas , Ensaios Clínicos como Assunto , Humanos , Imunofenotipagem/métodos , Masculino , Pessoa de Meia-Idade , Células-Tronco de Sangue Periférico/metabolismo , Cultura Primária de Células/métodos , Ratos
2.
Development ; 140(16): 3311-22, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23863483

RESUMO

Pluripotent mouse embryonic stem cells (mESCs), maintained in the presence of the leukemia inhibitory factor (LIF) cytokine, provide a powerful model with which to study pluripotency and differentiation programs. Extensive microarray studies on cultured cells have led to the identification of three LIF signatures. Here we focus on muscle ras oncogene homolog (MRAS), which is a small GTPase of the Ras family encoded within the Pluri gene cluster. To characterise the effects of Mras on cell pluripotency and differentiation, we used gain- and loss-of-function strategies in mESCs and in the Xenopus laevis embryo, in which Mras gene structure and protein sequence are conserved. We show that persistent knockdown of Mras in mESCs reduces expression of specific master genes and that MRAS plays a crucial role in the downregulation of OCT4 and NANOG protein levels upon differentiation. In Xenopus, we demonstrate the potential of Mras to modulate cell fate at early steps of development and during neurogenesis. Overexpression of Mras allows gastrula cells to retain responsiveness to fibroblast growth factor (FGF) and activin. Collectively, these results highlight novel conserved and pleiotropic effects of MRAS in stem cells and early steps of development.


Assuntos
Células-Tronco Embrionárias/enzimologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Xenopus laevis/embriologia , Ativinas/farmacologia , Sequência de Aminoácidos , Animais , Biomarcadores/metabolismo , Encéfalo/embriologia , Encéfalo/enzimologia , Sequência Conservada , Indução Embrionária , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Feminino , Fatores de Crescimento de Fibroblastos/farmacologia , Gástrula/citologia , Gástrula/efeitos dos fármacos , Gástrula/enzimologia , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fator Inibidor de Leucemia/farmacologia , Camundongos , Dados de Sequência Molecular , Proteínas Monoméricas de Ligação ao GTP/genética , Proteína Homeobox Nanog , Neurogênese , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Ovário/enzimologia , Xenopus laevis/genética , Xenopus laevis/metabolismo , Proteínas ras
3.
Stem Cell Rev Rep ; 8(1): 1-15, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21537995

RESUMO

LIF, a member of the IL6 family of cytokine, displays pleiotropic effects on various cell types and organs. Its critical role in stem cell models (e.g.: murine ES, human mesenchymal cells) and its essential non redundant function during the implantation process of embryos, in eutherian mammals, put this cytokine at the core of many studies aiming to understand its mechanisms of action, which could benefit to medical applications. In addition, its conservation upon evolution raised the challenging question concerning the function of LIF in species in which there is no implantation. We present the recent knowledge about the established and potential functions of LIF in different stem cell models, (embryonic, hematopoietic, mesenchymal, muscle, neural stem cells and iPSC). We will also discuss EVO-DEVO aspects of this multifaceted cytokine.


Assuntos
Fator Inibidor de Leucemia/fisiologia , Transdução de Sinais , Células-Tronco/fisiologia , Animais , Expressão Gênica , Regulação da Expressão Gênica , Pleiotropia Genética , Humanos , Fator Inibidor de Leucemia/genética , Fator Inibidor de Leucemia/metabolismo , Células-Tronco/metabolismo , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/metabolismo
4.
Eur Cytokine Netw ; 20(2): 51-62, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19541590

RESUMO

The aim of this article is to recapitulate the key features of leukaemia inhibitory factor cytokine (LIF), to review its numerous physiological effects and to comment on the most recent data. We will also present results of transcriptome analyses, which have highlighted different categories of LIF targets, identified in murine embryonic stem (ES) cells and early derivatives. We hope to stimulate new research fields on this puzzling cytokine, which, forty years after its discovery, has still not disclosed all its secrets.


Assuntos
Fator Inibidor de Leucemia/fisiologia , Animais , Diferenciação Celular/fisiologia , Implantação do Embrião/fisiologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Exostose Múltipla Hereditária/genética , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Infertilidade Feminina/metabolismo , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/deficiência , Subunidade alfa de Receptor de Fator Inibidor de Leucemia/genética , Camundongos , Osteocondrodisplasias/genética , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Gravidez , Receptores de OSM-LIF/classificação , Receptores de OSM-LIF/fisiologia , Fator de Transcrição STAT3/fisiologia , Transdução de Sinais , Especificidade da Espécie , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/fisiologia
5.
BMC Genomics ; 10: 73, 2009 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-19203379

RESUMO

BACKGROUND: Mouse embryonic stem (ES) cells remain pluripotent in vitro when grown in the presence of the cytokine Leukaemia Inhibitory Factor (LIF). Identification of LIF targets and of genes regulating the transition between pluripotent and early differentiated cells is a critical step for understanding the control of ES cell pluripotency. RESULTS: By gene profiling studies carried out with mRNAs from ES cells and their early derivatives treated or not with LIF, we have identified i) LIF-dependent genes, highly expressed in pluripotent cells, whose expression level decreases sharply upon LIF withdrawal [Pluri genes], ii) LIF induced genes [Lifind genes] whose expression is differentially regulated depending upon cell context and iii) genes specific to the reversible or irreversible committed states. In addition, by hierarchical gene clustering, we have identified, among eight independent gene clusters, two atypical groups of genes, whose expression level was highly modulated in committed cells only. Computer based analyses led to the characterization of different sub-types of Pluri and Lifind genes, and revealed their differential modulation by Oct4 or Nanog master genes. Individual knock down of a selection of Pluri and Lifind genes leads to weak changes in the expression of early differentiation markers, in cell growth conditions in which these master genes are still expressed. CONCLUSION: We have identified different sets of LIF-regulated genes depending upon the cell state (reversible or irreversible commitment), which allowed us to present a novel global view of LIF responses. We are also reporting on the identification of genes whose expression is strictly regulated during the commitment step. Furthermore, our studies identify sub-networks of genes with a restricted expression in pluripotent ES cells, whose down regulation occurs while the master knot (composed of OCT4, SOX2 and NANOG) is still expressed and which might be down-regulated together for driving cells towards differentiation.


Assuntos
Células-Tronco Embrionárias/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Fator Inibidor de Leucemia/metabolismo , Camundongos/genética , Animais , Diferenciação Celular/genética , Linhagem Celular , Análise por Conglomerados , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Células-Tronco Pluripotentes/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA